Norseman terminals - sealant?

[greenalien]

I am in the process of renewing the standing rigging on my boat. All the rigging wires have Norseman terminals at the lower end, which I shall be reusing, with new cones.
When initially installed, no sealant was used - they have lasted 25 years, but on disassembly, some of the old cones were somewhat corroded. I have heard that it's recommended to fill the terminals with sealant - is this a good idea, and if so, silicone or polysulphide?

 

[vyv_cox]

I use Sikaflex for virtually every sealing job on board, including this one. I avoid silicones, their mechanical strength is poor and they inhibit many reactions and adhesion, e.g. epoxies, polyesters, paint, etc. The unique beauty of polysulphides is that they are available in small squeezy tubes for occasional little jobs but I saw recently that Sikaflex is also available like this.

 

[greenalien]

The unique beauty of polysulphides is that they are available in small squeezy tubes for occasional little jobs but I saw recently that Sikaflex is also available like this

Interestingly, 100ml tubes of Sikaflex 291 cost only a little less than 300ml cartridges - is the shelf life very bad once it's opened?

 

[vyv_cox]

You can usually get away with leaving a 300 ml tube with clingfilm over the nozzle for a month or so. By that time the whole spout is usually solid, removing that leaves a solid bit in the screwed fitting on the tube which can usually be drilled out or maybe poked out with a small screwdriver or a large wood screw. After a season it will be solid most of the way down the tube, the remainder can be used by punching a hole in the side of the tube, but only once.

Some people seem to have had success with freezing the open tube but our freezer compartment on board is always crammed full with food. Fridge was not successful.

 

[danielefua]

I am in the process of renewing the standing rigging on my boat. All the rigging wires have Norseman terminals at the lower end, which I shall be reusing, with new cones.
When initially installed, no sealant was used - they have lasted 25 years, but on disassembly, some of the old cones were somewhat corroded. I have heard that it's recommended to fill the terminals with sealant - is this a good idea, and if so, silicone or polysulphide?

A Norseman leaflet I happened to read once, recommends the use of a sealant and suggests the procedure to apply it. Most important, it strongly discourages the use of acetic acid based sealants (i.e. silicone): apparently the latter may damage stainless steel.

Daniel

 

[Blueboatman]

I replaced all the rigging with Stalok ( Norsemen) fittings on my last boat and yup, recommendations were non-acetic silicone or higher grade sealants such as polyurethanes ( Sikaflex).

Acetic silicones, funnily enough, smell of vinegar when opened, quite strongly too

 

[merlin3688]

Sta Lok and Norseman are different companies, this is what Sta Lok say from the Sta Lok website.

Interior water proofing is not essential but will prevent water collecting in the bottom of the fitting.

To water proof the STA-LOK terminal: -
Unscrew the socket assembly from the end fitting.
Fill the end fitting approximately ¼ full with caulking*.
Re-assemble.
Remove excess caulking from the top of the fitting.
The STA-LOK Terminal is reusable however a new wedge must be used.
* Caulking use boat life lifecaulk, 3m 101 polysulfide or similar

 

[greenalien]

I think I'll go the Sikaflex route - my main concern with the whole sealant idea was that theoretically, there can sometimes be problems with crevice corrosion if stainless steel is deprived of oxygen, which the sealant would do. However, corrosion of the Norseman cones, which is a definite, although minor, problem, would be avoided.

 

[vyv_cox]

I think I'll go the Sikaflex route - my main concern with the whole sealant idea was that theoretically, there can sometimes be problems with crevice corrosion if stainless steel is deprived of oxygen, which the sealant would do.

Corrosion needs water - crevice corrosion is far more likely if you don't seal the fitting than if you do.

Info on crevice corrosion can be found on my website.

 

[LadyInBed]

corrosion of the Norseman cones, which is a definite, although minor, problem, would be avoided.

I use Norseman and am about to shorten my (two) back-stays. I have new cones from S3i (p&p was almost as much as the cost of the cones ), it will be interesting to see the condition of the old ones which have been sealed.